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Tuesday, January 1, 2013

Darkness and Now Redemption

Folks have been complaining that last month (December has 2012) was one of the worst in memory. Dark, wet, and dark again. But was this our imagination? Let us cast light on this darkness!

Let's begin by examining a plot of cumulative solar radiation on my department's roof since the beginning of December through the end of the month (the numbers on the bottom are the number of hours into the month). This is a measure of the total solar radiation you could have soaked up at any point in the month. The black line is for December 2012 and red is normal (past 13 year average). For the first few days we were getting normal sun, but then we started falling behind more and more. Yes my friends it was darker much than normal.

But we can go further. December 2012 is tied for darkest December with December 2007. So December 2012 was as bad as we have seen during this century! That is enough to give nearly anyone a bad case of SAD (Seasonal Affective Disorder) and turn on their interior floodlights.

But there bright, lustrous` news..today January 1 is virtually clear over much of western Washington and Oregon. Don't believe me? Look outside or check out the latest image from my department's web cam looking towards Mt. Rainier.

Some of you near the water have some fog right now, but most of that will burn off. Only those in the fog/stratus laden basin of eastern Washington will be denied the sun's face.

The visible satellite picture Tuesday morning shows a cloudy eastern Washington and east-slope valleys. Clear skies over the crest, western slopes, and most of the lowlands. Only in the Chehalis and Willamette Valleys and the Strait can you see some shallow fog

Happy New Year, Cliff.This week we received a burn ban in Snohomish and Pierce counties. King does not have one. I've seen this a few times. Driving from a clear Bellevue last night we encounter fog in Canyon Park as we drove into Snohomish Co. So, is the a reason why King County is clear? Elevation difference, more upper level wind? Or is it politics that keeps the burn ban off in King Co.?

Pardon the somewhat nerdy questions, but is the variation from normal statistically significant (I'd be surprised if it wasn't)and out of curiosity, how "noisy" is the data from year to year for December, i.e. how much variation is there.

As I recall, last spring the long-term forecasters were saying that La Nina was gone and we had shifted into an El Nino pattern, indicating that we would have a drier-than-normal winter (as I understand it).

Since that's obviously not what has transpired, I was wondering if you would please address this in a future post.